Currently, full-metal outer shells are being used more and more in wireless communication devices due to advantages thereof, such as beautiful appearance, high structural strength, excellent thermal conductivity and the like. Wireless communication device generally transfers an electromagnetic signal through an antenna device, however, the antenna device is easily shielded and interfered with by the metal outer shell when the signal is received and transmitted.
In order to overcome the signal shielding and interference, the outer shell of the wireless communication device in the prior art is generally composed of two parts, that is metal parts and a nonmetal spacer. An antenna radiation unit is designed to the nonmetal spacer of the outer shell, so that radiation of the antenna is not shielded by the metal parts or effect of the metal parts on radiation of the antenna is reduced to the greatest extent. However, such a prior art cannot achieve the full-metal outer shell, instead, non-metal spacer is added to reduce the shielding of radiation of the antenna, thereby affecting not only aesthetics and structural strength, but also complicating manufacturing process and increasing cost.
Meanwhile, a MIMO technology (Multiple Input Multiple Output, MIMO, refers to the use of multiple transmitting antennas at a transmitting end and multiple receiving antennas at a receiving end) is increasingly becoming a key technology of the wireless communication device. In order to achieve MIMO operation, two or more receiving antennas and transmitting antennas operating at the same frequency are needed. However, since multiple antennas operate simultaneously, signal interference easily occurs between the antennas, thereby affecting efficiency of receiving and transmitting signal.
Using MIMO technology with the full-metal outer shell, how to ensure that the signal is not affected by the metal outer shell and different antennas can operate simultaneously without causing signal interference between different antennas has become an important project troubling industry.